
/* Copyright (c) Mark J. Kilgard, 1994. */

/* This program is freely distributable without licensing fees
   and is provided without guarantee or warrantee expressed or
   implied. This program is -not- in the public domain. */

/**
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED
 * Permission to use, copy, modify, and distribute this software for
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission.
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * US Government Users Restricted Rights
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */
/*
 *  scene.c
 *  This program demonstrates the use of the GL lighting model.
 *  Objects are drawn using a grey material characteristic.
 *  A single light source illuminates the objects.
 */
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <GL/glut.h>

#define BUFSIZE 512

#define TORUS		1
#define TETRAHEDRON	2
#define ICOSAHEDRON	3

GLuint selectBuf[BUFSIZE];

int W = 500, H = 500;
GLfloat x, y;
int locating = 0;
int theObject = 0;
int menu_inuse = 0;
int mouse_state = 0;

char *objectNames[] =
{"Nothing", "Torus", "Tetrahedron", "Icosahedron"};

void
output(GLfloat x, GLfloat y, char *format,...)
{
	va_list args;
	char buffer[200], *p;

	va_start(args, format);
	vsprintf(buffer, format, args);
	va_end(args);
	glPushMatrix();
	glTranslatef(x, y, 0);
	for (p = buffer; *p; p++)
		glutStrokeCharacter(GLUT_STROKE_ROMAN, *p);
	glPopMatrix();
}

/* Initialize material property and light source. */
void
myinit(void)
{
	GLfloat light_ambient[] =
	{0.2, 0.2, 0.2, 1.0};
	GLfloat light_diffuse[] =
	{1.0, 1.0, 1.0, 1.0};
	GLfloat light_specular[] =
	{1.0, 1.0, 1.0, 1.0};
	GLfloat light_position[] =
	{1.0, 1.0, 1.0, 0.0};

	glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
	glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
	glLightfv(GL_LIGHT0, GL_POSITION, light_position);

	glEnable(GL_LIGHT0);
	glDepthFunc(GL_LESS);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_LIGHTING);

	glSelectBuffer(BUFSIZE, selectBuf);

	glNewList(TORUS, GL_COMPILE);
	glutSolidTorus(0.275, 0.85, 10, 15);
	glEndList();
	glNewList(TETRAHEDRON, GL_COMPILE);
	glutSolidTetrahedron();
	glEndList();
	glNewList(ICOSAHEDRON, GL_COMPILE);
	glutSolidIcosahedron();
	glEndList();
}

void
highlightBegin(void)
{
	static GLfloat red[4] =
	{1.0, 0.0, 0.0, 1.0};

	glPushAttrib(GL_LIGHTING_BIT | GL_CURRENT_BIT);
	glMaterialfv(GL_FRONT, GL_DIFFUSE, red);
	glColor3f(1.0, 0.0, 0.0);
}

void
highlightEnd(void)
{
	glPopAttrib();
}

void
draw(void)
{
	glPushMatrix();
	glScalef(1.3, 1.3, 1.3);
	glRotatef(20.0, 1.0, 0.0, 0.0);

	glLoadName(2);
	glPushMatrix();
	if (theObject == 2)
		highlightBegin();
	glTranslatef(-0.75, -0.5, 0.0);
	glRotatef(270.0, 1.0, 0.0, 0.0);
	glCallList(TETRAHEDRON);
	if (theObject == 2)
		highlightEnd();
	glPopMatrix();

	glLoadName(1);
	glPushMatrix();
	if (theObject == 1)
		highlightBegin();
	glTranslatef(-0.75, 0.5, 0.0);
	glRotatef(90.0, 1.0, 0.0, 0.0);
	glCallList(TORUS);
	if (theObject == 1)
		highlightEnd();
	glPopMatrix();

	glLoadName(3);
	glPushMatrix();
	if (theObject == 3)
		highlightBegin();
	glTranslatef(0.75, 0.0, -1.0);
	glCallList(ICOSAHEDRON);
	if (theObject == 3)
		highlightEnd();
	glPopMatrix();

	glPopMatrix();
}

void
myortho(void)
{
	if (W <= H)
		glOrtho(-2.5, 2.5, -2.5 * (GLfloat) H / (GLfloat) W,
		        2.5 * (GLfloat) H / (GLfloat) W, -10.0, 10.0);
	else
		glOrtho(-2.5 * (GLfloat) W / (GLfloat) H,
		        2.5 * (GLfloat) W / (GLfloat) H, -2.5, 2.5, -10.0, 10.0);
}

/*  processHits() prints out the contents of the
 *  selection array.
 */
void
processHits(GLint hits, GLuint buffer[])
{
	GLuint depth = ~0;
	unsigned int i, getThisName;
	GLuint names, *ptr;
	GLuint newObject;

	ptr = (GLuint *) buffer;
	newObject = 0;
	for (i = 0; i < hits; i++) {  /* for each hit  */
		getThisName = 0;
		names = *ptr;
		ptr++;              /* skip # name */
		if (*ptr <= depth) {
			depth = *ptr;
			getThisName = 1;
		}
		ptr++;              /* skip z1 */
		if (*ptr <= depth) {
			depth = *ptr;
			getThisName = 1;
		}
		ptr++;              /* skip z2 */

		if (getThisName)
			newObject = *ptr;
		ptr += names;       /* skip the names list */
	}
	if (theObject != newObject) {
		theObject = newObject;
		glutPostRedisplay();
	}
}

/* ARGSUSED */
void
locate(int value)
{
	GLint viewport[4];
	GLint hits;

	if (locating) {
		if (mouse_state == GLUT_ENTERED) {
			(void) glRenderMode(GL_SELECT);
			glInitNames();
			glPushName(-1);

			glMatrixMode(GL_PROJECTION);
			glPushMatrix();
			glLoadIdentity();
			viewport[0] = 0;
			viewport[1] = 0;
			viewport[2] = W;
			viewport[3] = H;
			gluPickMatrix(x, H - y, 5.0, 5.0, viewport);
			myortho();
			glMatrixMode(GL_MODELVIEW);
			draw();
			glMatrixMode(GL_PROJECTION);
			glPopMatrix();
			glMatrixMode(GL_MODELVIEW);
			hits = glRenderMode(GL_RENDER);
		} else {
			hits = 0;
		}
		processHits(hits, selectBuf);
	}
	locating = 0;
}

void
passive(int newx, int newy)
{
	x = newx;
	y = newy;
	if (!locating) {
		locating = 1;
		glutTimerFunc(1, locate, 0);
	}
}

void
entry(int state)
{
	mouse_state = state;
	if (!menu_inuse) {
		if (state == GLUT_LEFT) {
			if (theObject != 0) {
				theObject = 0;
				glutPostRedisplay();
			}
		}
	}
}

void
display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	draw();

	glPushAttrib(GL_ENABLE_BIT);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_LIGHTING);
	glDisable(GL_LINE_SMOOTH);

	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();
	gluOrtho2D(0, 3000, 0, 3000);
	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();
	output(80, 2800, "Automatically names object under mouse.");
	output(80, 100, "Located: %s.", objectNames[theObject]);
	glPopMatrix();
	glMatrixMode(GL_PROJECTION);
	glPopMatrix();
	glMatrixMode(GL_MODELVIEW);
	glPopAttrib();

	glutSwapBuffers();
}

void
myReshape(int w, int h)
{
	W = w;
	H = h;
	glViewport(0, 0, W, H);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	myortho();
	glMatrixMode(GL_MODELVIEW);
}

void
polygon_mode(int value)
{
	switch (value) {
	case 1:
		glEnable(GL_LIGHTING);
		glDisable(GL_BLEND);
		glEnable(GL_DEPTH_TEST);
		glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
		break;
	case 2:
		glDisable(GL_LIGHTING);
		glColor3f(1.0, 1.0, 1.0);
		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
		glEnable(GL_LINE_SMOOTH);
		glEnable(GL_BLEND);
		glDisable(GL_DEPTH_TEST);
		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
		break;
	}
	glutPostRedisplay();
}

void
mstatus(int status, int newx, int newy)
{
	if (status == GLUT_MENU_NOT_IN_USE) {
		menu_inuse = 0;
		passive(newx, newy);
	} else {
		menu_inuse = 1;
	}
}

void
main_menu(int value)
{
	if (value == 666)
		exit(0);
}

/*  Main Loop
 *  Open window with initial window size, title bar,
 *  RGBA display mode, and handle input events.
 */
int
main(int argc, char **argv)
{
	int submenu;

	glutInit(&argc, argv);
	glutInitWindowSize(W, H);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutCreateWindow(argv[0]);
	myinit();
	glutReshapeFunc(myReshape);
	glutDisplayFunc(display);
	submenu = glutCreateMenu(polygon_mode);
	glutAddMenuEntry("Filled", 1);
	glutAddMenuEntry("Outline", 2);
	glutCreateMenu(main_menu);
	glutAddMenuEntry("Quit", 666);
	glutAddSubMenu("Polygon mode", submenu);
	glutAttachMenu(GLUT_RIGHT_BUTTON);
	glutPassiveMotionFunc(passive);
	glutEntryFunc(entry);
	glutMenuStatusFunc(mstatus);
	glutMainLoop();
	return 0;             /* ANSI C requires main to return int. */
}
